It would be the world's first such system and is intended to move the marijuana industry away from its cash-only roots.

The plan has bipartisan support.

"This is the final piece to our pot puzzle," said the proposal's chief sponsor, Representative Jonathan Singer, who is a Democrat.

Colorado recently became the first state to allow the sale of pot for recreational uses.

Colorado collected about $2m in marijuana taxes in January

Backers of the bills said the cash-only nature of the industry makes pot businesses targets for crime, limits owners' access to credit and capital and hinders the state's ability to track revenues for tax-collection purposes.

The bill would allow marijuana sellers to pool money in cooperatives, but the co-ops would only take effect if the US Federal Reserve agrees to allow them to do things like accept credit cards or checks.

The so-called "cannabis credit co-ops" bill was passed by the state’s legislature and now goes to Governor John Hickenlooper for approval.

Mr Hickenlooper supports the pot bank plan and is expected to sign it into law, though a spokesman has said the governor had yet to review the final language.